Frequent disconnects: No Response received, T3 time-out

Hi,

I've been getting a lot of connection drops lately, some taking quite a while to recover.

Modem+Router: Netgear C7000v2
Adapter: Netgear A7000

At first I thought it had to do with the A7000 or with congested channels. After doing troubleshooting on both of those, I read some posts on this forum about similar errors found in modem logs. I'm thinking it maybe has more to do with the cable lines themselves.

After reaching the house, the line runs through two splitters. One is a 1-to-3 that only has one line running out and could probably just be coupled. Another is a 1-to-2 which runs a line to an upstairs bedroom but which I don't actually need or use. Some of the lines are rather old and bent as well. I'm thinking at least eliminating those splitters would help reliability, but I'd prefer to have a technician do it in case it's decided the lines also should be replaced.

Thanks for any help you can give. I've included what I could gather below. Please let me know if you'd like me to provide anything else.

Log

At any given point in time, the log looks similar to this (connection active/"OK"):

2023-1-24, 09:59:44	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:59:43	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:59:25	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:59:23	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:57:43	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:57:43	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:57:24	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:57:23	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:55:43	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:55:43	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:55:23	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:55:23	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:53:45	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:53:43	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:53:23	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:53:23	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:51:48	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:51:43	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:51:24	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:51:23	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:49:47	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:49:44	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:49:24	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:49:24	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:47:44	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:47:44	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:47:25	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:47:24	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:45:44	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:45:44	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:45:26	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:45:24	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:43:45	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:43:44	Warning (5)	Dynamic Range Window violation
2023-1-24, 09:43:26	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;

When connection drops, I'm seeing this. (Sorry, no pretty formatting ... just copied from a text log):

2023-1-20, 16:30:50 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:30:42 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:30:31 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:30:14 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:29:29 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:29:10 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2023-1-20, 16:29:02 Warning (5) B-INIT-RNG Failure - Retries exceeded;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:27:23 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:27:21 Warning (5) B-INIT-RNG Failure - Retries exceeded;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:25:15 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:25:02 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;

Channel information (found this in Basic -> Cable Connection after searching 10 minutes through the Advanced section. Yes, certainly basic stuff, Netgear!)

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectables
1	Locked	QAM256	25	573000000 Hz	3.2 dBmV	39.2 dB	95	135
2	Locked	QAM256	21	549000000 Hz	3.3 dBmV	39.2 dB	134	225
3	Locked	QAM256	22	555000000 Hz	3.4 dBmV	39.3 dB	161	125
4	Locked	QAM256	23	561000000 Hz	3.3 dBmV	38.6 dB	83	123
5	Locked	QAM256	24	567000000 Hz	3.2 dBmV	39.3 dB	118	163
6	Locked	QAM256	37	645000000 Hz	3.7 dBmV	39.3 dB	142	162
7	Locked	QAM256	26	579000000 Hz	3.1 dBmV	39.1 dB	232	140
8	Locked	QAM256	27	585000000 Hz	2.8 dBmV	38.7 dB	142	178
9	Locked	QAM256	28	591000000 Hz	2.8 dBmV	38.7 dB	142	191
10	Locked	QAM256	29	597000000 Hz	3.1 dBmV	38.8 dB	142	144
11	Locked	QAM256	30	603000000 Hz	3 dBmV	38.8 dB	159	249
12	Locked	QAM256	31	609000000 Hz	3 dBmV	38.8 dB	135	162
13	Locked	QAM256	32	615000000 Hz	3.1 dBmV	38.7 dB	140	210
14	Locked	QAM256	33	621000000 Hz	3.2 dBmV	39 dB	112	149
15	Locked	QAM256	34	627000000 Hz	3.4 dBmV	39.1 dB	133	136
16	Locked	QAM256	35	633000000 Hz	3.6 dBmV	39.3 dB	198	251
17	Locked	QAM256	36	639000000 Hz	2.8 dBmV	39 dB	0	0
18	Locked	QAM256	38	651000000 Hz	2.7 dBmV	38.9 dB	0	0
19	Locked	QAM256	39	657000000 Hz	2.8 dBmV	39 dB	0	0
20	Locked	QAM256	40	663000000 Hz	2.7 dBmV	39 dB	0	0
21	Locked	QAM256	41	669000000 Hz	2.9 dBmV	39 dB	0	0
22	Locked	QAM256	42	675000000 Hz	2.8 dBmV	38.6 dB	0	0
23	Locked	QAM256	43	681000000 Hz	2.9 dBmV	39 dB	0	0
24	Locked	QAM256	44	687000000 Hz	2.7 dBmV	38.7 dB	0	0

Upstream Bonded Channels (Partial Service)

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	13	5120 Ksym/sec	35600000 Hz	45.8 dBmV
2	Not Locked	Unknown	9	0 Ksym/sec	10400000 Hz	0.0 dBmV
3	Not Locked	Unknown	10	0 Ksym/sec	16400000 Hz	0.0 dBmV
4	Not Locked	Unknown	11	0 Ksym/sec	22800000 Hz	0.0 dBmV
5	Not Locked	Unknown	12	0 Ksym/sec	29200000 Hz	0.0 dBmV
6	Locked	ATDMA	14	2560 Ksym/sec	40400000 Hz	45.8 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV

Thanks again.

This conversation is no longer open for comments or replies and is no longer visible to community members.

Responses

EG

Expert

•

111.4K Messages

2 years ago

@EmailMeToTheMoon

Please redact all of the CM MAC and the CMTS MAC addresses in your error log entries for your privacy. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically. It flagged your post as "Private".

EmailMeToTheMoon

Visitor

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5 Messages

@EG

Thank you for that. I was wondering why I was seeing "Private". I've removed everything. Please let me know if there's anything else that needs cleaning up.

(edited)

2 years ago

EG

Expert

•

111.4K Messages

2 years ago

@EmailMeToTheMoon

You're good to go. The post is publicly viewable again.

That said. The signal status values at that snapshot in time were OK but the error log entries indicate that something is going on. And there are only 2 upstream channels locked in. Should be 3 to 6. Perhaps there is noise ingress into the line(s) / an upstream channel / return path impairment somewhere. That can be the cause of the un-bonding of the channels.

There are other signal stat values that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.

I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They will be able to poll the CMTS (Cable Modem Termination System) to check for any real-time degradation and / or error reports, see your node / cable plant, and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !

EmailMeToTheMoon

Visitor

•

5 Messages

@EG Thanks again! Really appreciated.

2 years ago

XfinityJohnG

Official Employee

•

1.9K Messages

Thank you very much for reaching out to our team here. I will be happy to look into any service issue from here for you. Could you send me a direct message with the full name and complete address for your service?

To send a direct message [private message]:

Click the "Direct Message" icon or https://forums.xfinity.com/direct-messaging

Click the "New message" (pencil and paper) icon

The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there.

- As you are typing a drop-down list appears. Select "Xfinity Support" from that list.

- An "Xfinity Support" graphic replaces the "To:" line.

Type your message in the text area near the bottom of the window

Press Enter to send it

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer. tick

2 years ago

EmailMeToTheMoon

Visitor

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5 Messages

Thanks for offering to look into it. I sent a DM to Xfinity Support per the instructions.

2 years ago

EG

Expert

•

111.4K Messages

@EmailMeToTheMoon @XfinityJohnG

Please circle back here and post any possible solutions for the issue here in the open forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

2 years ago

EG

Expert

•

111.4K Messages

2 years ago

Quite welcome !

EmailMeToTheMoon

Visitor

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5 Messages

2 years ago

The technician came out and was able to resolve the issue. (Thread started 5 hours ago! Talk about a fast turnaround time.)

Up the pole, there were some wires exposed. When it rained, the process of collecting moisture and drying out was causing interference. I was experiencing intermittent issues, with the connection being fine for days at a time, and then seeing 4-5 disconnects in a day. Being in winter now, weather being more of a factor makes sense, seeing more disconnects in the past few wet months.

Also worth mentioning: apparently an electrical tech had installed a filter on the line in response to the exposed wire. This was why I was down to two bonded upstream channels. Now I've got 6 up, and things are looking stable.

Appreciate everyone who had a role in getting this resolved so quickly! If I should mark an answer as the solution, please let me know.

EG

Expert

•

111.4K Messages

2 years ago

Not surprised about the high pass filter. Glad that you got it squared away so quickly !

Your Home Network

EmailMeToTheMoon

Frequent disconnects: No Response received, T3 time-out

EG

EmailMeToTheMoon

EG

EmailMeToTheMoon

XfinityJohnG

EmailMeToTheMoon

EG

EG

EmailMeToTheMoon

EG

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